Late last month, in a flurry of plastic tubs and cardboard boxes, the most heavily populated city block in Oregon shifted -- but not by much. That designation now belongs on the next block over, where more than 800 Portland State students moved into brand-new student housing.

The 978-bed University Pointe apartment building takes the crown from the block where PSU's Broadway dorm is located, which had been the most-dense block in the state at the time of the 2010 Census. And that block, in turn, had taken over the designation from the site of PSU's Ondine dorm, which was densest in the 2000 census.

The pattern is unmistakable, and its impact on businesses and residents in downtown Portland is no less so. The school's push to bring more of its student body into on- or near-campus housing -- University President Wim Wiewel has said he wants to see 25 percent of students living in the university district from roughly 10 percent now -- has become perhaps the biggest development initiative in one of the most visible parts of the city.

"You can really tell there's twice as many people at PSU there were 25 years ago," said Charles Rynerson, a demographer at the Population Research Center at PSU, and a student at the school in the mid-80s. "There are just a lot more bodies walking across campus."

The newest apartment building's massive scale is the product of a partnership between the university and a Texas company that has built student housing at more than 170 campuses across the country.American Campus Communities, a publicly traded real estate investment trust, built the $90 million University Pointe.

The private firm and its investors -- who maintain and manage the building, and collect the rent -- get to tap into the higher education boom. Outfits like ACC now run dorms across the country for schools that didn't want to take on a multimillion-dollar construction project on their own. In this case, PSU gets a new on-campus housing option without the construction debt.

The university, like other urban campuses across the country, collected classroom space block by block over the years, and paid little consideration to what happened after evening classes wrapped up.

But school officials realized foregoing the campus atmosphere, complete with 24-hour student residents, came with a cost. They now say students benefit from living on or near campus, where they can use the school's out-of-the-classroom resources and, research shows, boost their GPA.

"One of the barriers of choosing an urban university is that challenge of, 'Where will I live?'" said Jackie Balzer, the school's vice president for enrollment and student affairs. "Our whole goal is that they (American Campus Communities) build an environment that promotes success."

The land under University Pointe stays with PSU but will be leased to ACC. In 65 years -- with the possibility of two 10-year extensions -- the building itself transfers to university ownership, too.

Other private developers working independently of the school are also building new housing as close to campus as they can, including Eugene-based Master Capital Management, which is building an 8-story, 129-bed apartment building with ground-floor retail just across the street from University Pointe.

A recently approved urban renewal district around the university will likely draw even more development. It's expected to raise $169 million by 2041 for redevelopment, including money the school will use to add to its classroom space and $46 million for affordable housing.

More 24-hour residents means more demand for local shops and services, and that's a need the district isn't yet ready to meet, said Craig Sweitzer of Urban Works Real Estate. He said clients like pubs and breweries, pizza joints and ice cream shops have looked at the area and largely walked away.

"They would love to be in that neighborhood, but there hasn't been that kind of space," Sweitzer said.

But each infusion of new 24-hour residents increases the temptation as campus starts to feel a little more vibrant after classes end for the day.

"You're not just selling lunchtime," said Sweitzer. "A lot of retailers, particularly food venders, really survive and make money on evening trade. Kids who live there, they want to go do stuff."